From: Eric Sesterhenn Since all sanity checks rely on the validity of s_start which gets only checked to be smaller than s_end, we should also check if s_end is sane. Now we also try to retrieve the last block of the filesystem, which is computed by s_end. If this fails, something is bogus. Signed-off-by: Eric Sesterhenn Acked-by: Tigran Aivazian Signed-off-by: Andrew Morton --- fs/bfs/inode.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff -puN fs/bfs/inode.c~bfs-check-that-filesystem-fits-on-the-blockdevice fs/bfs/inode.c --- a/fs/bfs/inode.c~bfs-check-that-filesystem-fits-on-the-blockdevice +++ a/fs/bfs/inode.c @@ -390,6 +390,18 @@ static int bfs_fill_super(struct super_b - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS; info->si_freei = 0; info->si_lf_eblk = 0; + + /* can we read the last block? */ + bh = sb_bread(s, info->si_blocks - 1); + if (!bh) { + printf("Last block not available: %lu\n", info->si_blocks - 1); + iput(inode); + ret = -EIO; + kfree(info->si_imap); + goto out; + } + brelse(bh); + bh = NULL; for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) { struct bfs_inode *di; _